Biomedical subjects

K W Grätz

Publications and source records attributed to K W Grätz.

At least 19 recordsLinked to original sources

PubMed2006

Clinical experiences with bisphopsphonate induced osteochemonecrosis of the jaws.

QUESTION: Bisphosphonates are frequently used drugs in the adjuvant therapy of bone metastases and tumour-induced hypercalcaemia, but also for osteoporosis or Pagets disease. Several publications within the last three years considered osteonecrosis of the jaws to be connected with bisphosphonate therapy. Until today possible treatment strategies contain antibiotics, hyperbaric therapy and operative treatment. The tendency of healing however seems to be extremely poor. All clinicians should be aware of this new kind of side effect of bisphosphonate therapy. METHODS: 14 patients with this new kind of osteonecrosis were admitted to the department of Cranio-Maxillofacial Surgery of the University Hospital of Zurich. 8 men and 6 women all received bisphosphonates for cancer therapy. A complete analysis of patients' data was performed. RESULTS: Of 14 patients in 7 the underlying disease disease was multiple myeloma. In one patient it was prostate cancer and in all female patients it was breast cancer. All of them had prior dental treatment and showed inflammatory signs and bacterial colonisation with localisation in the upper or lower jaw or in both. CONCLUSION: The infectious part of the bisphosphonate-induced osteonecrosis (ONJ) is considered to be more important than thought before. We presume that antimicrobial treatment is of utmost importance in the treatment of this kind of osteonecrosis. Patients with current or previous bisphosphonate therapy should be treated multidisciplinary to assure ideal prevention and treatment.

Adult↗

PubMed2006

The galea fascia flap in orbital reconstruction: innovative harvest technique.

AIM: To report the treatment of a recurrent adenoid-cystic carcinoma of the lacrimal gland required orbital exenteration with an en bloc resection of the lateral orbital rim and wall and an anterior portion of the temporal muscle. Reconstruction was planned with both the objectives of a shortened healing time for faster epithetic reconstruction and no visible scars. METHOD: After a cranially extended temporal approach, the dissection of the superficial galea layer was connected with the subcutaneous dissection of the upper and lower eyelid after subciliary incisions. RESULTS: Ample exposure of the temporal, frontal and orbital region was obtained, facilitating the orbital exenteration with en bloc resection of the lateral orbital rim and wall and the anterior portion of the temporal muscle. The epithelialization of the eye socket covered with the galea fascia flap was accelerated, providing faster epithetic reconstruction, without visible scars. CONCLUSIONS: Healing time is accelerated, providing faster epithetic rehabilitation without visible scars, which is important in the postoperative rehabilitation ladder after eye exenteration for both patient and surgeon. Further more ablative surgery within this region gets safer and easier due to the ample exposure of this innovative surgical technique. Further evaluation of the effectiveness and safety of this new approach is advisable.

Carcinoma, Adenoid Cystic↗

PubMed2005

[Solitary abscessing osteomyelitis of the mandibular condyle. A rarity].

CASE REPORT: We report on a rare case of secondary chronic osteomyelitis of the left condyle. Haemophilus aphrophilus could be isolated from the abscess material. The condyle was resected and reconstructed with an endoprosthesis in the same operation. DISCUSSION: Possible causes of the rare location of secondary chronic osteomyelitis are assembled in a review of the literature and compared with the actual case. CONCLUSION: We suggest the inoculation of microorganisms through the needle of a local anesthetic injection, bacterial contamination during the tooth extraction, or bacteremia following the dental extraction to be possible causes for the infection.

Abscess↗

PubMed2005

[Condylar metastasis. Review of the literature and report of a case].

BACKGROUND: Metastases in the mandibular condyle are rare. A survey of the literature showed that only 23 of 69 selected cases qualified under the criteria of Meyer and Shklar. REPORT OF A CASE: A 48-year-old white male suffering from a previously operated lung carcinoma was referred due to pain and discomfort in the left TMJ. A solitary condylar metastasis of the mandible was revealed. Because of diffuse tumorous infiltration into periarticular tissue, irradiation treatment was performed. During the long-term follow-up growth of additional skeletal metastases occurred. DISCUSSION: The course of condylar metastases in general is similar to other metastases involving the jaw. Breast cancer as the primary tumor is most frequent, followed by lung cancer. There are no specific clinical or radiological parameters leading to diagnosis. The clinician should take a potential metastasis into account when dealing with TMJ complaints, radiological oddities, and medical history of malignant tumors. For proper treatment planning, diagnosis should be based on histology. Since the diagnosis of metastasis is usually made at an advanced stage of disease, therapy will be mainly intended as palliative.

Bone Marrow↗

PubMed2003

Impact of whole body positron emission tomography on initial staging and therapy in patients with squamous cell carcinoma of the oral cavity.

The aim of this study is to evaluate the additional clinical information provided by whole body positron emission tomography (PET) with fluorodeoxyglucose (FDG) for initial staging of patients with squamous cell carcinoma (SCC) of the oral cavity. PET scans from the head to the pelvic floor of 34 consecutive patients (22 male, 12 female; mean age 71 years) with histologically confirmed SCC of the oral cavity were retrospectively evaluated. Clinical information including CT of the head and neck and chest X-Ray or chest CT was compared with information on nodal involvement and distant metastases or secondary tumours obtained with PET. The primary tumour was identified with PET in 33 of 34 patients (97%). In 27 Patients (81%) the clinical N-stage was confirmed with PET. In two Patients (6%) additional pathologic loco-regional lymph nodes were found. In five patients more lymph nodes were identified with CT. Distant lesions were seen with PET imaging in bone, lung, mediastinum, liver and colon. In three patients (6%) distant metastases were correctly identified. In another four patients (12%) a secondary cancer was detected. One false positive finding was described with PET. In five of 34 patients (15%) the additional findings as revealed with PET lead to a change of treatment. Whole body PET provides relevant additional information to a standard clinical staging procedure in patients with oral cavity SCC. The detection of distant metastases and secondary primary tumours can have a great impact on patient management.

Aged↗

PubMed2003

Laser-induced temperature changes in dentine.

OBJECTIVE: The purpose of this work is to study the temperature rise and potential thermal damage caused during ablation of human dentine using a super pulsed carbon dioxide laser of 9.6-microm wavelength, equipped with a water-cooling spray and scanner system. BACKGROUND DATA: There have been no reports on thermal effects of super pulsed CO2 laser of 9.6 microm wavelength on human dentine recently. MATERIALS AND METHODS: Two different types of samples were investigated to yield data most consistent with a typical clinical situation. Human dentine slices and crown segments were studied at a drilling depth of 1.0 +/- 0.1 mm and 2.5 +/- 0.5 mm, respectively. A control group treated with a conventional hand piece was compared to four laser groups with settings varying from 2 to 8 W. RESULTS: In the laser group demonstrating the highest elevation in temperature of the four studied, dentine slices lased at 2 W for 15 sec showed a mean temperature rise of less than 1.68 degrees C at an ablation rate of 0.86 +/- 0.08 mm. Conventional drilling with a comparable ablation rate of 0.76 +/- 0.59 mm resulted in a mean rise of 2.87 degrees C. The laser groups of crown segments revealed a constant decrease in temperature. SEM observations were lacking the typical morphological changes seen in earlier studies, specifically extensive melting, charring or cracking. CONCLUSION: A maximum rise of mean temperature to 1.68 degrees C in closest vicinity to the pulpal chamber and the morphological unaltered dentine surfaces demonstrate the safe and tissue preserving character of the superpulsed 9.6 microm CO2 laser. The laser caused an even lower temperature rise than conventional drilling. Moreover, the laser showed acceptable efficacy with ablation rates that did not significantly differ from the conventional dental drill.

Body Temperature↗

PubMed2003

Surgical removal of a dislocated lower third molar from the condyle region: case report.

INTRODUCTION: Migration of dislocated lower third molar into the condylar region is quite rare. Attention should be taken to avoid condyle fracture. METHODS: 49-year-old patient had an ectopic lower left third molal in the condylar region, suffered from a submandibular and masseter space abscess. Removal of the molar via intraoral approach was chosen avoiding facial nerve branches and unnecessary scar formation. Coronoid process is removed, the tooth is separated and removed. The defect is filled with iliac cancellous bone. The coronoid process was fixed as a cover with a resorbable plate and screws (BIONX). RESULTS: Removal via intraoral approach is possible. Hypesthesia existed postoperatively, became normal later. CONCLUSION: Annual observation is strongly recommended. Intraoral approach is superior to the extraoral approach. Removal of the coronoid process minimizes the masticator forces. Separation of the tooth is essential. Filling the defect with cancellous bone accelerates the healing.

Abscess↗

PubMed2002

Slow and continuous application of human recombinant bone morphogenetic protein via biodegradable poly(lactide-co-glycolide) foamspheres.

Bone morphogenetic proteins (BMPs) are multifunctional cytokines that were originally identified as molecules that induce bone and cartilage formation in vivo. In order to increase the efficacy of this potent protein for application in medicine, a carrier system is needed to retain the BMP at the preferred site. Here we present and characterize a slow-release carrier system for pure human recombinant (rh)BMP. The large porous microspheres, called 'foamspheres', are biodegradable, because they consist of poly(lactide-co-glycolide) acids and release loaded rhBMP slowly and continuously. In vivo studies in rodents revealed that rhBMP-loaded foamspheres increased the thickness of the calvarial bone of rats by 222%. When the same amount of rhBMP was applied via a gelatine-based hydrogel, the increase in bone height was only 66%. Thus, the carrier system for rhBMP is an important factor for the efficacy of BMPs.

Absorbable Implants↗

PubMed2001

Disulfide bridge conformers of mature BMP are inhibitors for heterotopic ossification.

Heterotopic ossification is a frequent complication in patients who have suffered head and neck traumas or undergone total hip replacement. Heterotopic ossification occurs when osteogenic precursor cells present at the ectopic site receive the necessary signal(s) to differentiate into osteoblasts. At the protein level, the key factors in differentiation of cells to the osteogenic lineage are BMPs. Stable BMP variants derived from the identical amino acid sequence but with different disulfide bridge configurations have been investigated and found to be capable of inhibiting ossification in vitro and in vivo in rodents. These findings provide a concept for the straightforward development of a novel class of BMP antagonists that could lead to new treatments for traumatically and genetically induced heterotopic ossification and also, possibly, for disorders in which other members of the TGF-beta superfamily are involved.

Animals↗

PubMed2000

Temperature mapping of magnetic resonance-guided laser interstitial thermal therapy (LITT) in lymphangiomas of the head and neck.

BACKGROUND AND OBJECTIVE: Lymphangiomas of the tongue and neck are uncommon benign congenital lymphatic tumors. These vascular lesions are difficult to treat, frequently recur, and can cause patients significant morbidity. Treatment may also be complicated by adjacent vital anatomic structures. Magnetic resonance (MR)-controlled laser-induced interstitial thermotherapy (LITT) has been proven to be a noninvasive safe treatment. Real-time monitoring of tissue temperature with thermosensitive sequences allows controlled coagulation necrosis. STUDY DESIGN/MATERIALS AND METHODS: LITT was performed in a lymphangioma specimen ex vivo. In four patients (eight procedures) with lymphangiomas of the tongue and neck, MR-guided LITT was performed with a percutaneous approach in a multiapplicator technique. The laser system consisted of a titanium catheter and a protective catheter. The dome of the fiber end had a diameter of 1.4 mm with an active length of 20 mm. Temperature sensitive sequences were used in a 0.5 T open-configured MR scanner with the proton frequency shift technique to map the spatial and temporal distribution of Nd:YAG laser effects (7 Watts, 30 pulses per second, 10 minutes/location). Postoperative MR follow-up was performed at 1 week and at 3 months. In three patients, partial resection of the tumor was performed 6 months after LITT. RESULTS: In three patients, MR clearly showed a diminished tumor volume. All four patients reported subjective amelioration and in three patients former functional problems, such as speech and swallowing were improved. MR thermometry allowed accurate demarcation of changes by heat and distinction of affected tumor volume (3.0 cm +/- 0.3 cm). The histology of the patients 6 months after LITT showed laser-induced fibrosis of former lymphatic tissue. CONCLUSION: The results suggest that LITT can be performed safely with tissue preserving of vital structures and can be effective in the treatment of deep tumors, such as lymphangiomas. However, given the nature of the lesion, the potential for recurrence exists no matter what modality is chosen.

Adult↗

PubMed1999

The Le Fort I osteotomy as a surgical approach for removal of tumours of the midface.

Tumours of the midface and maxillary sinuses have been removed via multiple approaches. The most common approaches are those using incisions in the facial skin, especially in the case of malignant tumours. The Le Fort I procedure via an intraoral incision as described by Sailer in 1986 is a versatile alternative. Combined with a coronal approach and various osteotomies of the upper face it also allows removal of tumours extending into the orbits, the nasoethmoidal complex and the skull base. The versatility of the Le Fort I osteotomy as a surgical approach was analysed in 17 cases. This method is reliable and gives excellent access. Further advantages are the wide surgical exposure and the clear visibility of the resection margins, the absence of visible scars, the feasibility of combining this approach with reconstruction using the buccal fat pad and the possibility of simultaneous placement of bone grafts, insertion of endosseous implants or other preprosthetic procedures via the same incision.

Adipose Tissue↗

PubMed1999

Frontal sinus fractures: computed tomography evaluation of sinus obliteration with lyophilized cartilage.

Allogenic lyophilized cartilage has been proven clinically to be a reliable material for obliteration of the frontal sinus without the limitations of donor site morbidity and the prolongation of the operation time produced by autogenic grafting. The long-term behaviour of the implanted material is of paramount importance for the success of the obliterative technique. This survey included 51 trauma patients on whom obliteration of the frontal sinus with lyophilized cartilage was performed. The fate of the lyophilized cartilage graft was evaluated from computed tomography imaging of the obliterated frontal sinus. No radiological sign of mucocele formation or inflammatory disease was noted. Bone density measurement of the obliterated sinus and the adjacent trabecular bone was calculated. The patient population was distributed into four groups (0-2, 2-4, 4-6, > 6 years) according the postobliterative time. The bone density of the implanted lyophilized cartilage was accentuated from group 1 to group 4 when compared with the bone density of the trabecular bone. This shows the long-term tendency of lyophilized cartilage graft to osseous substitution.

Adult↗

PubMed1998

[Fronto-orbital corrections and development of the frontal sinus].

The development of frontal sinuses following bilateral fronto-orbital advancement is a topic of controversial discussion in the literature. In a retrospective study on 33 patients (15 girls and 18 boys) the development of the frontal sinus was examined radiologically. Only patients with a minimum age of 6 years and with at least 1 year of postoperative follow-up were included. The radiological reference for the frontal sinus development consisted of pneumatisation at or above the level of the supraorbital rims, as projected din postero-anterior cephalograms. According to these criteria a frontal sinus development was seen in 72.7% of our patients. There was no statistically proven correlation between sinus development and the sex of the patient, age at surgery or the amount of advancement. With the exception of severe cases of Crouzon's disease we usually expect normal development of the frontal sinus following bilateral fronto-orbital correction.

Child↗

PubMed1998

[Cranial development after corrective skull surgery in craniosynostosis].

Craniofacial development may be potentially implicated after vault corrections in cases of craniosynostosis. The aim of this prospective study was the investigation of the surgical effect on calvaria growth, correlating the percentiles of a group of patients before and after craniosynostosis correction in relation to the normal percentiles of growth. The patient population consisted of 71 children; the postoperative follow-up time in 57 patients was more than 12 months. Of the children followed up, 36 were male and 21 female. Thirty-six cases involved untreated non-syndromic craniosynostosis; the remaining 21 were syndrome cases. The patient ages ranged from 16 to 27 months. In 11 cases correction of an occipital craniosynostosis was carried out. The fronto-occipital circumference was registered in accordance with Prader's percentile table. The operative method included a fronto-parietal craniotomy, the temporary removal and shaping of the fronto-orbital band and a vault cranioplasty. During follow-up 13 patients treated with fronto-orbital advancement in cases of isolated craniosynostosis remained in the registered percentile curve. In 13 patients a change to a lower percentile curve was confirmed; 1 patient changed to a higher curve. In cases of syndromic craniosynostosis 10 patients remained in the post-operatively registered percentile curve; 8 patients changed to a lower and 1 patient to a higher percentile curve. No growth restriction of the reshaped calvaria after surgical correction of craniosynostosis was observed. No significant difference was found in the potential calvaria growth between syndromic and isolated craniosynostosis.

Child, Preschool↗

PubMed1998

[Obliteration of the frontal sinus with lyophilized cartilage in frontal fractures].

Obliteration of the frontal sinus is frequently necessary in the appropriate treatment of major craniofacial trauma of the upper third of the face. Successful frontal sinus obliteration requires (1) meticulous removal of the frontal sinus mucosa, (2) permanent occlusion of the nasofrontal duct and (3) obliteration of the denuded cavity. The current techniques include implantation of autologous fat, bone or muscle. These techniques are effective when the appropriate guidelines are respected, but the problems of donor site morbidity, which has been as high as 5%, recipient site morbidity due to the shrinkage of the free graft, and the increase in the operative time must be pointed out. The unique characteristics of lyophilized cartilage, i.e. the low resorption rate and tendency to undergo osseous substitution, justify its use for obliteration of the frontal sinus. The present study reviews 51 patients with obliteration of the frontal sinus due to craniofacial trauma. In none of the patients were there clinical or radiological signs of postoperative mucocele formation. Progressive ossification of the implanted cartilage was verified in most of the patient population.

Adult↗

PubMed1998

[Occipital correction in scapho- and plagiocephaly].

The operation technique and the results after occipital correction in children with plagiocephaly and scaphocephaly are reported. The indication for the intervention is provided by aesthetic and functional considerations. The outcome is very good; the growth of the skull follows the same range of percentiles as preoperatively and normal mental development is seen.

Cephalometry↗

PubMed1998

Development of the frontal sinus following bilateral fronto-orbital osteotomies.

The presence of frontal sinuses following bilateral fronto-orbital advancement is discussed controversially in the literature. In a retrospective study, 33 patients (18 male and 15 female) were operated on between 1982 and 1993, with at least one year postoperative follow-up and with a minimum age of 6 years at the end of the follow-up period following bilateral fronto-orbital remodelling, were included. The average age at which the procedure was performed was 29 months with a minimum of 3 months and a maximum of 7.8 years. The study presented shows a pneumatization of the frontal sinus in 72.7% of 33 patients following bilateral fronto-orbital advancement. The first radiographic signs of sinus development were detected between the ages of 4 and 11, average 8.3 years. There were no statistically proven correlations between frontal sinus pneumatization and age at operation or the amount of advancement or sex of the patients. Surgical enlargement of the cranium by frontal advancement with adequate stabilization results in an enlargement of the neurocranium, thereby decreasing pressure on the inner frontal cortex and allowing frontal sinus pneumatization to proceed normally. Hence, the development of a frontal sinus may be a reflection of the effectiveness of the surgical therapy.

Age Factors↗

PubMed1998

Frontal sinus fractures: principles of treatment and long-term results after sinus obliteration with the use of lyophilized cartilage.

The most commonly used techniques for frontal sinus obliteration involve the implantation of an autogenous tissue graft: either fat, muscle or bone. Lyophilized allogenic cartilage due to its unique properties, such as the tendency to ossification and resistance to volume reduction, can be used as the material of choice for sinus obliteration. A clinical and radiological study of 66 patients operated on for frontal sinus fractures, between January 1 1988 through December 31 1995 was undertaken. Variables recorded included the aetiological factors, the clinical and radiological fracture features with the corresponding treatment modality, the association of frontal sinus fractures with intracranial involvement, the early and late postsurgical complications and the correlation between pre- and postoperative radiological findings. Obliteration of the frontal sinus with lyophilized cartilage chips was performed in 51 (77.3%) patients. The postsurgical evaluation showed no major complications. Revision of the frontal sinus was only required in one patient. The radiological findings verified the progressive calcification of the obliterated sinus. Allogenic lyophilized cartilage implantation offers distinct advantages in cases of severe frontal sinus trauma: 1. There is nearly unlimited availability of the material. 2. There is no need for a second operation field with the associated potential donor site morbidity. 3. The operation time is reduced due to the avoidance of a second operation on the donor site.

Adolescent↗